#include <iostream>
#include <string>
using namespace std;

void f(int a, int b)
{
    cout << "this is f(int, int)" << endl;
}

void f(double a, double b)
{
    cout << "this is f(double, double)" << endl;
}

int main()
{
    // f(1, 2.1); //  error: call to 'f' is ambiguous
    return 0;
}